Electrical communication apparatus



Feb. 24, 1942.

W. SPIEGEL ELECTRICAL COMMUNICATION APPARATUS 2 Sheets-Shet 1 Filed Dec. 26, 1939 Ibl OOQQQ Mn YINVENTOR.

ATTORNEY.

Feb. 24, 1942;. w. SPIEGEL 2,274,008

ELECTRICAL GOMMUNI CAT ION APPARATUS Filed Dec. 26, 1939 2 Sheets-Sheet 2 INVENTOR.

ATTORNEY.

Patented Feb. 24, 1942 ELECTRICAL COMMUNICATION APPARAT S Walter. Sp iegel, NewYork, N. f

I Application December 2 6, 1939,- Serial No. 310,906

11 claims. (01. 179-1) My invention relates to improvements in electrical intercommunication apparatus, and more particularly to switching circuits forsuch appa- The object ofthe invention is to provide a simple, efficient, switching arrangement forcommunicating apparatus whereby any master station will be'enabled to transmit and receive from any other master or any sub-station in the system. A further object is to, enable any substation to selectively transmit to and receive from any master station in the system. i

In devices of this nature it has heretofore been impossible for any particular sub-station to communicate with any but one master station in the system, and it has been desirable to allow any sub-station to select and communicate with any master station in the system, though it has been impossible to do so heretofore.

Eiribddimentsof'the invention are shown in theaccompanying drawings in which: Figurefl is a schematic wiring diagram of a master s'tation having a two stage audioamplifier and embodying my switching arrangement. Figure 2 is a diagrammatic view of a sub-station employ- Figure 3 is a block sub-statem is used to energize the plates and screens of tubes 4 and 5. The filaments of tubesl, 4, and are connected in series and are connected to the source of current, through resistance 6, which drops the voltage down tothat desired for energizing said filaments. As the amplifier itself is of conventional design, further explanation will be unnecessary.

In using the master station shown in Figure 1, to transmit to another master, the operation is as follows: I is a permanent magnet speaker, and when spoken into, its diaphragm vibrates and sets up electrical vibrations in coil 8, which are fed through line 9 to hook I0 and from hook I0 through line II to switch I2, and contact I2 and from contact I2 to one side of the primaryof transformer I3, and from the other side of. transformer I3 to lines I4 and I5 and to condenser I6,and by line H to ground l8. The current is induced in the secondary of transformer I3, and is amplified in the usual manner by tubes 4 and 5 and their associated circuits. The amplifiedc'urrent is induced from the primary of transformer I9 to its secondary winding, and through line I9 to contact 20 of switch 2I, and from switch 2I by line 22 to the selective switch 23, and by contact 24 to line 25 and binding post 26. The other side of the secondary of transformer I9 is fed through lines 21 and 28to ground I8 and from ground I8 to ground I8, to line H, condenser I6, line I5, common line I4 and to binding post 21, which latter and binding post 26 may be connected to a substation. r I I When transmitting from the master shown in Figure 1 to'another master station, switches 2I, I2 and 30 are thrown'to contacts 3|, 32, and 33 respectively, and when talking into speaker I, impulses are set up in line 9, through hook Ii], line II, switch I2, contact 32, and by line 33 to contact 3| of switch 2|, and from switch 2I- by line 22 to switch23, and by contact 34, through line 35 to terminal 36, and from terminal 36 to the particular master station desired and back to'terminal 21, through common line Land by line I5 to condenser I6, and line I! to ground I8, line 28, line 21 and to the opposite end of the voice coil.

When listening to the master shown in Figure 1,the switches 2 I, I2, and 30 are thrown to contacts 31, 3B, and 39, and the impulses transmitted from the'tran'smitting station are fed to terminal 40, by line 4| to contact 42 of switch 23, and from the latter by 1ine22 to switch 20,

- and from contact 31 of switch 20 to the primary of transformer I3, and from' the opposite end of said primary by line I4 to terminal 21 and back to the transmitting station.

The impulses set up in the secondary of the transformer I3 are amplified in the amplifier and are fed from the secondary of transformer I9 to line I9 contact 38 of switch I2, by line 43, and from switch I2 by line II to hook I0, and line 9 to one end of voice coil 8, and from the other end of voice coil 8 to ground I8 by lines 2! and 28. From ground I8, by line I! to condenser I6, common line I4, line I5, to terminal 21, by common line-I4 and line I5.

Switches 2|, I2, and 30 may be actuated by a common means as shown, or by other common means.

I In each instance I have used a successive contact of switch 23 leading to successive terminals in order, to show that the switch is a selective device. It is to be understood that each terminal is to be used for one line of a distant station, both when transmitting and receiving, and the other line of each station is attached to terminal 21.

When receiving by sub-station shown in Figure 2, impulses from the transmitting station are brought to any of the terminals of selector switch 45 and from there by lines 46 and 41 to hook 48, lines 49 and 50 to voice coil by lines 52 and 53 to common terminal 55 and back to the transmitting station. When using the sub-station to transmit switch 56 is thrown to contact 51 and impulses set up in coil 5| are fed to switch 56, by line 58, and contact 51, to switch 45, by line 46, and from said switch to any desired terminal, and from there to the station being transmitted to and back to voice coil 5| through I terminal 55 and common line 53.

Master stations 60 to 62 inclusive and substations 63 to 65 inclusive are shown suitably connected in Figure 3.

Of course it will be understood that various modifications may be made without departing from the spirit of the invention as claimed.

means for allowing operation of the translating device with or without the amplifying means in the circuit.

2. In an electric communication system of the character described, a master station having electronic amplifying means, switching means for disconnecting the amplifier when transmitting to stations equipped with amplifiers and for connecting the amplifier in circuit when transmitting to stations without amplifiers, said switching means being adapted to connect the amplifier in the circuit when receiving from any station.

3. An electric comunication system of the character described, a master station having an electronic amplifier, switching means for connecting the amplifier when transmitting to any station, said switching means being adapted to disconnect the amplifier from the circuit when receiving from stations employing amplifiers.

4. An electric communication system of the character described including a plurality of the master stations, each of said master stations employing amplifiers, a plurality of sub-stations, said substations not employing amplifiers, and means for selectively communicating by any substation with any master station.

5. An electric communication system of the character described including a plurality of the master stations, said master stations employing amplifiers, a plurality of sub-stations, said substations not employing amplifiers, means for selectively communication by any master with any sub-station, and means for selectively communicating by one station with another.

6. An electrical communication system of the character described; having a plurality of master-stations, each master-station including amplifiers; a plurality of sub-stations, said sub-stations being minus amplifiers; and means for selectively communicating by any sub-station with any master station.

7. An'electrical communication system of the character described; having a plurality of master-stations, each master-station including a vacuum tube amplifier; a plurality of sub-stations; and means for selectively communicating by any desired master-station with any substation to the exclusion of any other station.

8. An electrical communication system of the character described; having a plurality of master-stations and one or more sub-stations; and means for selectively communicating by any one master-station with any other master-station to the exclusion of all other stations.

9. An electrical communication system of the character described; having a plurality of master-stations, and one or more sub-stations; and means for selectively communicating by any one master-station with any other station, said means including electrical switching means for intermittent transmission and reception.

10. An electrical communication system of the character described; having a plurality of master-stations, each master-station including amplifying means; one or more sub-stations; and means for selectively communicating by any substation with any master-station, said means including electrical switching means for selectively connecting any sub-station with any desired master-station to the exclusion of all other stations.

11. In a communication system of the character described; a plurality of master-stations, each master-station including an amplifier and translating device, said translating device adapted to be employed alternately as a speaker and microphone; one or more sub-stations; switching means for selectively transmitting and receiving by any master-station to and from any other master or sub-station, said switching means being adapted to connect said translating device to the output circuit of said amplifier when receiving from a sub-station and to disconnect said translating device from said amplifier when receiving from a master-station.

WALTER SPIEGEL. 

